Padding bits for CSI report coding

Abstract

Described herein are methods and apparatus for jointly encoding components of a a channel state information (CSI) report into a single codeword. Padding bits are added to equalize payload size for different CRI/RI cases and to allow encoding of all parts of CSI into one codeword without payload ambiguity.

The invention claimed is: 
     
       1. An apparatus for a user equipment (UE), the apparatus comprising:
 one or more processors, wherein the one or more processors are configured to: 
 use a forward error correction code (FEC) to jointly encode all reported components of one or more channel state information (CSI) payloads that each represent a CSI report into a single codeword for transmission over a physical uplink control channel (PUCCH); 
 wherein the reported CSI payload components that are jointly encoded include one or more of: a CSI reference signal (CSI-RS) resource indicator (CRI), a rank indicator (RI), a layer indicator (LI), a precoding matrix indicator (PMI), or a channel quality indicator (CQI); and, 
 add a number of padding bits as necessary to the CSI payload before encoding to make the bitwidth of the CSI payload equal to a predetermined maximum allowable CSI payload bitwidth wherein the components of the CSI payload are ordered as follows: CR1, RI, LI, padding bits, PMI, and CQI. 
 
     
     
       2. The apparatus of  claim 1 , wherein the number of padding bits A padding  is calculated as:
 A padding  =A max   CSI −A CSI    
 
       where A CSI  is the bitwidth of the reported components of the CSI payload and A max   CSI  is the maximum allowable CSI payload bitwidth. 
     
     
       3. The apparatus of  claim 2 , wherein the bitwidth of the reported components of the CSI payload A CSI  is a function of the reported RI and wherein the maximum allowable CSI payload bitwidth A max   CSI  is a function of a set of allowed RI values. 
     
     
       4. The apparatus of  claim 1 , wherein the predetermined maximum allowable CSI payload bitwidth is determined by parameters to be received from a next generation Node B (gnB). 
     
     
       5. The apparatus of  claim 4 , wherein the parameters that determine the maximum allowable CSI payload bitwidth include a set of allowed RI values as indicated by higher layer parameter ri _ restriction. 
     
     
       6. The apparatus of  claim 4 , wherein the parameters that determine the maximum allowable CSI payload bitwidth include a CSI-RS resource set to be used for CSI reporting and the number of resources in the CSI-RS resource set. 
     
     
       7. The apparatus of  claim 4 , wherein the parameters that determine the maximum allowable CSI payload bitwidth include the number of CSI-RS ports. 
     
     
       8. The apparatus of  claim 1 , wherein the maximum allowable CSI payload bitwidth includes a maximum allowable PMI bitwidth that is a function of parameters to be received from a next generation Node B (gNB) that include the number of CSI- RS ports divided over two dimensions designated N 1  and N 2  and corresponding oversampling factors divided over two dimensions for codebook vectors referenced by the PMI designated as O 1  and O 2.    
     
     
       9. The apparatus of  claim 1 , wherein the maximum allowable CSI payload bitwidth A max   CSI  is calculated as:
 A max   CSI =max(A PMI (r)+A CQI (r)+A LI (r)) 
 
       where max(A PMI (r)+A CQI (r)+A LI (r)) is the maximum of the sum of the PMI bitwidth A PMI (r), the CQI bitwidth A CQI (r), and the LI bitwidth A LI (r) over a set of rank values allowed to be reported. 
     
     
       10. The apparatus of  claim 1 , wherein the FEC code is a polar code. 
     
     
       11. The apparatus of  claim 1 , wherein multiple CSI payloads representing multiple CSI reports are ordered sequentially to form a single encoder input bit sequence for encoding into the single codeword. 
     
     
       12. A user equipment (UE), the UE comprising:
 one or more memory mediums; and 
 one or more processors coupled to the one or more memory mediums, wherein the one or more processors are configured to cause the UE to: 
 use a forward error correction code (FEC) to jointly encode all reported components of one or more channel state information (CSI) payloads that each represent a CSI report into a single codeword for transmission over a physical uplink control channel (PUCCH), wherein the one or more memory mediums are configured to store the one or more CSI payloads; 
 wherein the reported CSI payload components that are jointly encoded include one or more of: a CSI reference signal (CSI-RS) resource indicator (CRI), a rank indicator (RI), a layer indicator (LI), a precoding matrix indicator (PMI), and a channel quality indicator (CQI); 
 add a number of padding bits as necessary to the CSI payload before encoding to make the bitwidth of the CSI payload equal to a maximum allowable CSI payload bitwidth, wherein the number of padding bits A padding  is calculated as: 
 A padding =A max   CSI −A CSI where A CSI  is the bitwidth of the reported components of the CSI payload and A max   CSI  is the maximum allowable CSI payload bitwidth; and, 
 wherein the bitwidth of the reported components of the CSI payload A CSI  is a function of the reported RI and wherein the maximum allowable CSI payload bitwidth A max   CSI  is a function of a set of allowed RI values to be received from a next generation Node B (gNB). 
 
     
     
       13. The UE of  claim 12 , wherein the maximum allowable CSI payload bitwidth A max   CSI  is further a function of parameters to be received from a next generation Node B (gNB) that include a CSI-RS resource set to be used for CSI reporting and the number of resources in the CSI-RS resource set. 
     
     
       14. The UE of  claim 12 , wherein the maximum allowable CSI payload bitwidth A max   CSI  is further a function of parameters to be received from a next generation Node B (gNB) that include the number of CSI-RS ports. 
     
     
       15. The UE of  claim 12 , wherein the padding bits are zeroes. 
     
     
       16. A non-transitory computer-readable storage medium comprising instructions to cause a user equipment (UE), upon execution of the instructions by one or more processors, to:
 use a forward error correction code (FEC) to jointly encode all reported components of one or more channel state information (CSI) payloads that each represent a CSI report into a single codeword for transmission over a physical uplink control channel (PUCCH); 
 wherein the reported CSI payload components that are jointly encoded include: a CSI reference signal (CSI-RS) resource indicator (CRI), a rank indicator (RI), a layer indicator (LI), a precoding matrix indicator (PMI), and a channel quality indicator (CQI); and, 
 add a number of padding bits as necessary to the CSI payload before encoding to make the bitwidth of the CSI payload equal to a predetermined maximum allowable CSI payload bitwidth wherein the components of the CSI payload are ordered as follows: CRI, RI, LI, padding bits, PMI, and CQI. 
 
     
     
       17. The medium of  claim 16 , wherein the number of padding bits A padding  is calculated as:
 A padding =A max   CSI  where A CSI  is the bitwidth of the reported components of the CSI payload and A max   CSI  is the maximum allowable CSI payload bitwidth. 
 
     
     
       18. The medium of  claim 16 , wherein the bitwidth of the reported components of the CSI payload A CSI  is a function of the reported RI and wherein the maximum allowable CSI payload bitwidth A max   CSI  is a function of the number of allowed RI values. 
     
     
       19. The medium of  claim 16 , wherein the predetermined maximum allowable CSI payload bitwidth is determined by parameters to be received from a next generation Node B (gNB). 
     
     
       20. The medium of  claim 16 , wherein the maximum allowable CSI payload bitwidth A max   CSI  is calculated as:
 A max   CSI =max(A PMI (r)+A CQI (r)+A LI (r)) 
 
       where max(A PMI (r)+A CQI (r)+A LI (r)) is the maximum of the sum of the PMI bitwidth A PMI (r), the CQI bitwidth A CQI (r), and the LI bitwidth A LI (r) over a set of rank values allowed to be reported.